A trend in semiconductor device manufacturing is to replace the silicon dioxide dielectric layer with a thinner dielectric layer. Materials suitable for thinner dielectric layers include polyimides, BCB and perylene. When polyimides are used, the semiconductor wafer is coated with the polyimide and the wafer is baked at 450.degree. C. for about one hour in order to solidify the polyimide and remove contaminants from the polyimide layer. Since oxygen reacts with the polyimide at high temperatures, the baking must be completed in an oxygen free environment, such as in a vacuum oven or in a diffusion furnace.
Prior art vacuum ovens comprise heavy stainless steel chambers and thus take a very long time to heat up to 450.degree. C. and cool back down to room temperature. Therefore, what is needed by semiconductor manufacturers is a vacuum oven that can be heated and cooled rapidly.